U.S. patent number 10,069,374 [Application Number 14/115,718] was granted by the patent office on 2018-09-04 for rotary electric machine having an heat sink with semiconductor modules attached.
This patent grant is currently assigned to Mitsubishi Electric Corporation. The grantee listed for this patent is Masahiko Fujita, Naohide Maeda. Invention is credited to Masahiko Fujita, Naohide Maeda.
United States Patent |
10,069,374 |
Maeda , et al. |
September 4, 2018 |
Rotary electric machine having an heat sink with semiconductor
modules attached
Abstract
A rotary electric machine in accordance with the invention
includes: a case including a front-side housing and a rear-side
housing; a rotor having a field winding placed in the case; a
stator having an armature winding placed in the case; a power
module for energizing armature current that flows in the armature
winding; a heat sink, on which the power module is mounted, for
cooling the power module; a field circuit module for controlling
field current that flows in the field winding; and a control
circuit for controlling the operation of the power module and the
field circuit module, wherein the power module includes a pair of
power modules mounted opposite to each other on a base surface of
the heat sink, and the heat sink includes a plurality of cooling
fins placed thereon.
Inventors: |
Maeda; Naohide (Chiyoda-ku,
JP), Fujita; Masahiko (Chiyoda-ku, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Maeda; Naohide
Fujita; Masahiko |
Chiyoda-ku
Chiyoda-ku |
N/A
N/A |
JP
JP |
|
|
Assignee: |
Mitsubishi Electric Corporation
(Tokyo, JP)
|
Family
ID: |
48167271 |
Appl.
No.: |
14/115,718 |
Filed: |
October 25, 2011 |
PCT
Filed: |
October 25, 2011 |
PCT No.: |
PCT/JP2011/074499 |
371(c)(1),(2),(4) Date: |
November 05, 2013 |
PCT
Pub. No.: |
WO2013/061404 |
PCT
Pub. Date: |
May 02, 2013 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20140070645 A1 |
Mar 13, 2014 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K
5/18 (20130101); H02K 9/04 (20130101); H02K
9/02 (20130101); H02K 11/33 (20160101); H02K
11/048 (20130101); H02K 9/06 (20130101); H02K
19/365 (20130101) |
Current International
Class: |
H02K
5/18 (20060101); H02K 11/04 (20160101); H02K
19/36 (20060101); H02K 9/06 (20060101); H02K
9/04 (20060101); H02K 9/02 (20060101) |
Field of
Search: |
;310/68D,68R,67R,71,52,64,60R,58 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1460749 |
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Sep 2004 |
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EP |
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1993192 |
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Nov 2008 |
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EP |
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2004-282905 |
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Oct 2004 |
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JP |
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2004282905 |
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Oct 2004 |
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JP |
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2005-86149 |
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Mar 2005 |
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JP |
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200586149 |
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Mar 2005 |
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JP |
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2007-336638 |
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Dec 2007 |
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JP |
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2007336638 |
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Dec 2007 |
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JP |
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2008-543263 |
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Nov 2008 |
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JP |
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WO 2010150529 |
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Dec 2010 |
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JP |
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2011-30405 |
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Feb 2011 |
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JP |
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2011-147319 |
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Jul 2011 |
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JP |
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2011-166948 |
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Aug 2011 |
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JP |
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2011166948 |
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Aug 2011 |
|
JP |
|
Other References
Yamasaki Masashi; Furumoto Atsushi; Kabune Hideki, Drive Device,
Dec. 29, 2010, Denso Corporation, WO2010150529. cited by examiner
.
Communication dated Aug. 10, 2015 from the European Patent Office
in counterpart application No. 11874579.3. cited by applicant .
Communication dated Jun. 26, 2015 from the State Intellectual
Property Office from the People's Republic of China in counterpart
application No. 201180071713.1. cited by applicant .
Communication dated Sep. 2, 2014 from the Japanese Patent Office in
counterpart Japanese Patent Application No. 2013540530. cited by
applicant .
Communication dated Dec. 22, 2016 from the European Patent Office
in counterpart European application No. 11874579.3. cited by
applicant.
|
Primary Examiner: Rojas; Bernard
Assistant Examiner: Singh; Alexander
Attorney, Agent or Firm: Sughrue Mion, PLLC Turner; Richard
C.
Claims
The invention claimed is:
1. A rotary electric machine comprising: a case including a
front-side housing and a rear-side housing; a rotor having a field
winding placed in the case; a stator having an armature winding
placed in the case; a power module for energizing armature current
that flows in the armature winding; a field circuit module for
controlling field current that flows in the field winding; and a
control circuit for controlling the operation of the power module
and the field circuit module, wherein a pair of divided heat sinks,
each having a base part that is parallel to an axial direction of
the rotor, each having a base surface that extends orthogonally
from the base part to an outside of the rotor and on which the
power module is mounted, and each having a plurality of fins for
cooling the power module that is placed on a side opposite to the
base surface of the base part, is provided, an integrated heat sink
assembly is configured by joining the base surface of one of the
heat sinks and the base surface of the other of the heat sinks, and
the power module is placed in a pair opposite to each other on the
base surface of one of the heat sinks and the base surface of the
other of the heat sinks.
2. The rotary electric machine according to claim 1, wherein the
heat sink comprises a fin that, when the heat sink is fixed to a
rotary electric machine, protrudes in the radial direction of the
rotary electric machine with respect to a part to which the power
module is fixed.
3. The rotary electric machine according to claim 1, wherein each
of the pair of divided heat sinks comprises a plurality of fins
that, when the heat sink assembly is fixed to a rotary electric
machine, protrude on both sides of the circumferential direction
with respect to a part to which the power module is fixed.
4. The rotary electric machine according to claim 3, wherein each
of the heat sinks comprises a plurality of fins that, when the heat
sink assembly is fixed to a rotary electric machine, protrudes on a
first side and a second side of the circumferential direction,
respectively, with respect to a part to which the power module is
fixed.
5. The rotary electric machine according to claim 1, wherein a
signal member including a signal wiring to the power module is
placed so as to be sandwiched between the base surfaces of the heat
sinks.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application
No. PCT/JP2011/074499, filed on Oct. 25, 2011, the contents of all
of which are incorporated herein by reference in their
entirety.
TECHNICAL FIELD
The present invention relates to a structure of a rotary electric
machine connected to an engine.
BACKGROUND ART
It is proposed that a heat sink is mounted on a conventional rotary
electric machine, the heat sink including: a fin protruding from
one base surface of the heat sink; and a module fixed to the
opposite base surface, the module having a switching device for
controlling armature current (for example, see PTL 1 and PTL
2).
Furthermore, PTL 3 proposes a drive apparatus integrated into a
motor, the apparatus having a heat sink to which semiconductor
modules are attached, each of the modules including a switching
device for one phase.
CITATION LIST
Patent Literature
PTL 1: JP-A-2011-147319
PTL 2: JP-T-2008-543263
PTL 3: JP-A-2011-30405
SUMMARY OF INVENTION
Technical Problem
It is proposed that in the above-described conventional rotary
electric machine described in the PTL 1, when a power circuit
module and a field circuit module that include a switching device
are mounted on a heat receiving part of a heat sink, the surface on
the heat sink side of the modules are machined into a convex shape
in order to maintain constant the distance between the modules and
the heat receiving part.
It is proposed that in the rotary electric machine described in the
PTL 2, a heat sink has a top surface on which an electronic
component is mounted and a back surface on which a fin is
configured, then the fin is placed between a rear housing of the
rotary electric machine and the electronic component, and then the
electronic component is cooled by air taken in in the radial
direction.
As described in the PTL 1 and PTL 2, the module is cooled by
cooling air flow taken in in the radial direction. However, these
rotary electric machines use a fan attached to a rotor the rotary
electric machine as a generator of the cooling air flow, the
cooling air flow being discharged in a direction from the rotation
shaft to the periphery of the rotor. A stator is placed along the
periphery of the rotor. So, the cooling air discharged from the fan
of the rotor cools the coil of the stator, then is discharged to
the outside of the rotary electric machine in the radial direction,
thereby being heated to high temperature. As described above, in
the PTL 1 and PTL 2, since air is taken in in the radial direction,
the heated air discharged from the rotary electric machine in the
radial direction may be taken in again, which raises a problem of
insufficient cooling capability.
Furthermore, since air is taker in in the radial direction and
discharged in the radial direction, the direction of the cooling
air flow needs to be changed by about 180 degree, which raises a
problem of large resistance leading to insufficient amount of the
cooling air flow.
Furthermore, in the PTL 1, a power module for a stator for
six-phases and a field module are placed on a base surface of a
planar heat sink. However, since the modules are placed almost
throughout the base surface, placing a component in the remaining
space in the same shaft direction is difficult because it may
elongate the length in the shaft direction of the overall rotary
electric machine or need too large size to contain within the
periphery of the stator of the rotary electric machine, so mounting
to an engine may be impossible.
Regarding the drive apparatus described in the PTL 3, in order to
reduce the size of the drive apparatus and improve the heat
dissipation capability of semiconductor modules in using the drive
apparatus as a power-assistance apparatus for vehicle, it is
proposed that the semiconductor modules are placed on the heat sink
in a vertical direction to reduce the size and the heat received
from an adjacent semiconductor module.
The PTL 3 proposes a motor for a power-assistance apparatus for
vehicle. Since, this type of motor assists in torque when a driver
steers, the rotor of the motor rotates only at low speed. So,
cooling effect is not expected from attaching a fan to the
rotor.
Accordingly, this motor is configured such that a fan for
generating cooling air flow and a fin of the heat sink is not
provided, and a semiconductor module is fixed to the heat sink
having a large heat capacity, then cooling is performed mainly by
transferring heat from the heat sink to a housing. So the cooling
capability provided by the structure of the PTL 3 may be
insufficient for a rotary electric machine that always operates to
drive power generation.
In order to solve the above problem, it is an object of the present
invention to provide a rotary electric machine that can have
sufficient cooling capability.
Solution to Problem
A rotary electric machine in accordance with the invention
includes: a case including a front-side housing and a rear-side
housing; a rotor having a field winding placed in the case; a
stator having an armature winding placed in the case; a power
module for energizing armature current that flows in the armature
winding; a heat sink, on which the power module is mounted, for
cooling the power module; a field circuit module for controlling
field current that flows in the field winding; and a control
circuit for controlling the operation of the power module and the
field circuit module, wherein the power module includes a pair of
power modules mounted opposite to each other on a base surface of
the heat sink, and the heat sink includes a plurality of cooling
fins placed thereon.
Furthermore, a rotary electric machine in accordance with the
invention includes: a case including a front-side housing and a
rear-side housing; a rotor having a field winding placed in the
case; a stator having an armature winding placed in the case; a
power module for energizing armature current that flows in the
armature winding; a heat sink, on which the power module is
mounted, for cooling the power module; a field circuit module for
controlling field current that flows in the field winding; and a
control circuit for controlling the operation of the power module
and the field circuit module, wherein the power module includes a
pair of power modules, the heat sink includes a pair of heat sinks,
one of the pair of power modules is mounted on one base surface of
the heat sink, the other of the pair of power modules is mounted on
the other base surface of the heat sink, the heat sink includes a
plurality of cooling fins placed thereon, and the respective base
surfaces of the heat sinks are joined to each other to configure a
heat sink assembly.
Advantageous Effects of Invention
According to the rotary electric machine in accordance with the
invention, the power module includes a pair of power modules
mounted opposite to each other on a base surface of the heat sink,
and the heat sink includes a plurality of cooling fins placed
thereon, which enhances the cooling capability of the rotary
electric machine.
Furthermore, according to the rotary electric machine in accordance
with the invention, the power module includes a pair of power
modules; the heat sink includes a pair of heat sinks; one of the
pair of power modules is mounted on one base surface of the heat
sink; the other of the pair of power modules is mounted on the
other base surface of the heat sink; the heat sink includes a
plurality of cooling fins placed thereon; and the respective base
surfaces of the heat sinks are joined to each other to configure a
heat sink assembly, which can enhance the cooling capability of the
rotary electric machine. Furthermore, each power module is fixed to
one side of the base surface of the heat sink, which can facilitate
the fabrication to reduce the manufacturing cost.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross-sectional view showing a rotary electric machine
in accordance with a first embodiment of the invention.
FIG. 2 is an electric circuit diagram showing the rotary electric
machine in accordance with the first embodiment of the
invention.
FIG. 3 is a plan view showing a heat sink assembly mounted on the
rotary electric machine in accordance with the first embodiment of
the invention.
FIG. 4 is a cross-sectional view showing the heat sink assembly in
the rotary electric machine in accordance with the first embodiment
of the invention.
FIG. 5 is a plan view showing a heat sink assembly mounted on a
rotary electric machine in accordance with a second embodiment of
the invention.
FIG. 6 is an axial cross-sectional view showing a heat sink
assembly in a rotary electric machine in accordance with a third
embodiment of the invention.
FIG. 7 is an axial cross-sectional view showing the heat sink
assembly in the rotary electric machine in accordance with the
third embodiment of the invention.
FIG. 8 is an axial cross-sectional view showing a heat sink
assembly in a rotary electric machine in accordance with a fourth
embodiment of the invention.
FIG. 9 is an axial cross-sectional view showing the heat sink
assembly in the rotary electric machine in accordance with the
fourth embodiment of the invention.
FIG. 10 is an axial cross-sectional view showing the heat sink
assembly in the rotary electric machine in accordance with the
fourth embodiment of the invention.
FIG. 11 is a cross-sectional view showing a heat sink assembly in a
rotary electric machine in accordance with a fifth embodiment of
the invention.
DESCRIPTION OF EMBODIMENTS
First Embodiment
A first embodiment of the invention is described below with
reference to FIGS. 1 to 4. Through the drawings, the same or
corresponding members or portions are denoted by the same numerals.
FIG. 1 is a cross-sectional view showing a rotary electric machine
in accordance with the first embodiment of the invention. FIG. 2 is
an electric circuit diagram showing the rotary electric machine in
accordance with the first embodiment of the invention. FIG. 3 is a
plan view showing a heat sink assembly mounted on the rotary
electric machine in accordance with the first embodiment of the
invention. FIG. 4 is a cross-sectional view showing the heat sink
assembly in the rotary electric machine in accordance with the
first embodiment of the invention.
In the following embodiment, a rotary electric machine is described
as an example. When used as a motor, the rotary electric machine
can restart an engine connected thereto. When used as a generator,
the rotary electric machine can supply power to a vehicle and
charge a battery.
Referring to FIG. 1, a rotary electric machine 1 of the first
embodiment includes, for example: a case 4 including a front-side
housing 2 and a rear-side housing 3 that are made of aluminum; a
shaft 6 that is provided in the case 4 and has a pulley 5 attached
to one end thereof; a rotor 7 mounted on the shaft 6; a front fan 8
(e.g., a centrifugal fan) for generating cooling air flow, mounted
on the rotor 7 on the front-side housing 2 side; a rear fan 9
(e.g., a centrifugal fan) for generating cooling air flow, mounted
on the rotor 7 on the rear-side housing 3 side; a stator 10 fixed
to the front-side housing 2 and the rear-side housing 3 on the
inner wall surface of the case 4; a slip ring 11 fixed to the other
end of the shaft 6 for supplying field current to the rotor 7; a
pair of brushes 12 that slide over the slip ring 11; and a brush
holder 13 that is fixed to the rear-side housing 3 and contains the
brushes 12.
Note that the pulley 5 is connected to an internal combustion
engine (not shown) by a belt for transferring power to/from the
internal combustion engine. Furthermore, field current is supplied
to the rotor 7 through the brushes 12 from the brush holder 13 that
has the slip ring 11 and is fixed to the rear-side housing 3
side.
The rotor 7 includes: a field winding 14 that is formed by winding
a wire and generates magnetic flux when current flows therein; and
a field core 15 that is provided to cover the field winding 14 and
has a magnetic pole formed by the magnetic flux.
The field core 15 includes a pair of a first pole core body 16 and
a second pole core body 17 that are fit to each other. The first
pole core body 16 and the second pole core body 17 are made of iron
and have nail-shaped magnetic poles 18 and 19, respectively. The
nail-shaped magnetic poles 18 and 19 adjacent to each other are
placed to form a certain width of inter-magnetic pole gap so that
magnetic flux leakage will not occur between the nail-shaped
magnetic poles and the inter-magnetic pole gap will work as a
cooling air flow passage for cooling the field winding 14.
The stator 10 includes: a stator core 20; and an armature winding
21 in which a wire is wound around the slot (not shown) of the
stator core 20 and, when the rotor 7 rotates, alternating current
is generated in response to change in the magnetic flux of the
field winding 14. For example, the armature winding 21 includes a
three-phase AC winding in which three windings (not shown) are
connected in three-phase Y connection or three-phase .DELTA.
connection.
The front-side housing 2 and the rear-side housing 3 are coupled to
each other with a fastening bolt to sandwich the stator core 20
between the front-side housing 2 and the rear-side housing 3.
A rotation sensor 22 is attached to the shaft 6 on the brush holder
13 side. The rotary electric machine 1 includes a control circuit
23 for controlling a field circuit and a switching circuit, for
example, on the periphery of the brush holder 13. A field circuit
module 24 for causing field current to flow according to an
instruction from the control circuit 23 is provided. The field
current is adjusted by the field circuit so that a required torque
or power can be generated. The field circuit is packaged into the
field circuit module 24 that is mounted on the rotary electric
machine 1.
A switching device for supplying armature current in working as a
motor and rectifying armature current in working as a generator is
provided as a power module 25 into which the switching device for
one phase and a peripheral circuit are integrated. Then, the power
modules 25 for three phases are placed so as to be separated from
one another, as shown in FIG. 3. The power module 25 is mounted on
a heat sink 26 for cooling and fixed to the rear-side housing
3.
The power module 25 is fixed by bonding or the like to a
predetermined place on a base surface 27 of the heat sink 26 for
cooling. The power modules 25 are placed so as to sandwich the base
surface 27 of the heat sink 26 therebetween to configure one heat
sink assembly 28.
In order to protect the power module 25, the field circuit module
24, the control circuit 23 and the like, a cover 29 for covering
them is mounted on the rear side of the rotary electric machine 1.
Note that a battery 30 is shown in FIG. 2.
An operation of the rotary electric machine in accordance with the
first embodiment of the invention is described. When the rotary
electric machine 1 operates as a motor, the control circuit 23
instructs the field circuit module 24 to cause field current to
flow and then the field winding 14 is energized. Next, three-phase
AC current wave shape is caused to flow in the power module 25 to
rotate the rotor 7, thereby generating a torque.
On the other hand, when the rotary electric machine 1 operates as a
generator, the control circuit 23 receives an request for a current
to be generated, from an external controller, and instructs the
field circuit of the field circuit module 24 to cause field current
to flow according to the requested current to be generated.
Furthermore, the control circuit 23 measures phase voltage and,
when the phase voltage exceeds output voltage, instructs the power
module 25 to switch the switching device, thereby rectifying AC
current generated in the armature winding 21 into DC current.
FIG. 4 is a cross-sectional view of the heat sink assembly 28 of
the first embodiment of the invention. In the first embodiment of
the invention, the stator 10 has a plurality of sets of three-phase
armature windings 21, and includes the power module 25 for each
phase.
The power module 25 is fixed by bonding or the like to the
predetermined place on the base surface 27 of the heat sink 26 for
cooling. The power modules 25 are placed so as to sandwich the base
surface 27 of the heat sink 26 therebetween to configure one heat
sink assembly 28.
The heat sink assembly 28 is mounted on the rotary electric machine
1 such that the base surface 27 of the heat sink 26 on which the
power module 25 is mounted is perpendicular to the shaft 6 of the
rotary electric machine 1. A case 31 into which a wiring to the
power module 25 and the like are inserted is placed around the base
surface 27 of the heat sink 26, and a terminal of the power module
25 is connected to the case 31.
The heat sink 26 includes a fin 32 protruding from the base surface
27 inwardly in the radial direction of the rotary electric machine
1. The cover 29 shown in FIG. 1 includes an air intake port 33
formed so that air can be taken in from the rotation shaft
direction to the fin 32.
Furthermore, the cover 29 includes a side wall from the rear-side
end face of the rotary electric machine 1 to the rear-side housing
3 to prevent air intake from the radial direction. Furthermore, an
opening of the case 31 opposite the base surface 27 of the heat
sink 26 is covered by a protection cover 34 for protecting the
power module 25. As shown in FIG. 4, a protection cover 35 of an
opening on the rear side may include a signal line and an output
wiring for connecting to the control circuit 23.
An effect of this embodiment is described. Two power modules 25 are
placed so as to sandwich the base surface 27 of the heat sink 26
therebetween, which can reduce the footprint of the power modules
25 in the radial cross section in the rotary electric machine 1,
thereby reducing the size of the rotary electric machine 1 and
enhancing the cooling capability by placing the fin 32 of the heat
sink 26 in the remaining space.
Furthermore, the fin 32 is protruded inwardly in the radial
direction, which can ensure a sufficient length of the fin 32 to
enhance the cooling capability. Furthermore, cooling air flow is
taken in from the shaft direction and taking in air from the radial
direction is prevented, which enables effective cooling.
As described above, according to the first embodiment, the power
modules 25 are placed so as to sandwich the base surface 27 of the
heat sink 26 therebetween, which can reduce the footprint of the
power modules 25 in the radial cross section in the rotary electric
machine 1 and correspondingly allows reservation of a larger area
for the fin 32 of the heat sink 26, thereby enhancing the cooling
capability. Furthermore, the fin 32 of the heat sink 26 is
configured to be cooled by cooling air flow that is parallel to the
rotation shaft 6, which prevents the intake of air discharged from
the radial direction of the rotary electric machine 1 and reduces
the resistance when cooling air flow passes, thereby enhancing the
cooling capability of the rotary electric machine 1.
Furthermore, the fin 32 of the heat sink 26 is configured to
protrude in the radial direction, which allows reservation of a
larger area for the fin 32 of the heat sink 26. Furthermore, since
the rear-side fan 9 of the rotor 7 takes in air from the rotation
shaft direction and discharges air toward the periphery, the fin 32
is protruded toward the inner radius, which causes cooling air flow
to efficiently flow along the fin 32, resulting in further
enhancement of the cooling capability of the rotary electric
machine 1.
Second Embodiment
A second embodiment of the invention is described with reference to
FIG. 5. FIG. 5 is a plan view showing a heat sink assembly mounted
on a rotary electric machine in accordance with a second embodiment
of the invention.
Generally, the structure and operation of the second embodiment are
the same as those of the above-described first embodiment.
Similarly to the above-described first embodiment, in the second
embodiment, two power modules 25 are mounted so as to sandwich a
base surface 27 of a heat sink 26 therebetween, and a fin 36 is
protruded from the base surface 27 of the heat sink 26 generally in
the circumferential direction when mounted on the rotary electric
machine 1. A case 31 into which a wiring to the power module 25 and
the like are inserted is placed around the base surface 27 of the
heat sink 26, and a terminal of the power module 25 is connected to
the case 31.
The power module 25 needs to be connected to an armature winding
21. So, in order to facilitate connection between them, the power
module 25 and the armature winding 21 are placed adjacent to each
other in the circumferential direction. As shown in the second
embodiment, the power modules 25 is placed so as to sandwich the
base surface 27 of the heat sink 26 therebetween, which facilitates
reservation of a space in the circumferential direction for the fin
36 and can efficiently place the fin 36 so as to enhance the
cooling effect.
On the other hand, a signal wiring, an output wiring and the like
can be placed on the inner- and outer-circumference side, which
facilitates effective space utilization to reduce the size of the
rotary electric machine.
According to the second embodiment, the heat sink 26 is placed so
that, when mounted on the rotary electric machine 1, the fin 36
protrudes from the base surface 27 of the heat sink 26 in the
circumferential direction. Especially, in the rotary electric
machine having a plurality of three-phase winding as described in
the PTL 1, the power modules are placed throughout the surface in
the radial direction, which makes it difficult to take in cooling
air flow from the shaft direction. However, placing the power
modules 25 so as to sandwich the base surface 27 of the heat sink
26 therebetween as shown in the second embodiment can reduce the
space on which the power modules 25 are placed. Correspondingly,
the fin 36 can be placed so as to protrude in the circumferential
direction, allowing cooling air flow to be taken in from the shaft
direction, which can take in cooler air and reduce the resistance
of the air flow passage, thereby more efficiently cooling the power
modules 25.
Third Embodiment
A third embodiment of the invention is described with reference to
FIGS. 6 and 7. Through the drawings, the same or corresponding
members or portions are denoted by the same numerals. FIG. 6 is an
axial cross-sectional view showing a heat sink assembly in a rotary
electric machine in accordance with the third embodiment of the
invention. FIG. 7 is an axial cross-sectional view showing the heat
sink assembly in the rotary electric machine in accordance with the
third embodiment of the invention.
A heat sink assembly 37 of the third embodiment includes: a power
module 25 mounted on a base surface 27 of a heat sink 26; and a
case 31, into which a wiring to the power module 25 and the like
are inserted, placed around the base surface 27 and connected with
a terminal of the power module 25. Specifically, the heat sink
assembly 37 is divided into: a portion as shown in FIG. 6(b) in
which one power module 25 is mounted on a base surface 27 of one
heat sink 26 and then a case 31 and a protection cover 35 are
provided; and a portion as shown in FIG. 6(c) in which one power
module 25 is mounted on a base surface 27 of one heat sink 26 and
then a case 31 and a protection cover 34 are provided, and then
these portions are integrated into the heat sink assembly 37 as
shown in FIG. 6(a).
Next, the base surfaces 27 of the two heat sinks 26 on which the
power modules 25 are not mounted are joined and fixed to each
other. Fixing the heat sinks 26 to each other can be performed by
applying an adhesive or the like between the base surfaces 27 or
applying a heat-conductive grease or the like between the base
surfaces 27 and mechanically fixing the heat sinks 26 with
additional parts using a screw or the like.
The third embodiment is configured so that a fin 32 protrudes from
the base surface 27 of the heat sink 26 toward the inner radius in
the rotary electric machine 1. Such a configuration of the heat
sink assembly 37 can reduce the footprint of the power module 25 in
the radial cross section in the rotary electric machine 1, thereby
reducing the size of the rotary electric machine 1 and enhancing
the cooling capability by placing the fin 32 of the heat sink 26 in
the remaining space.
Furthermore, the fin 32 is protruded inwardly in the radial
direction, which can ensure a sufficient length of the fin 32 to
enhance the cooling capability. Furthermore, cooling air flow is
taken in from the shaft direction and taking in air from the radial
direction is prevented, which enables effective cooling.
Furthermore, regarding the power modules 25 mounted on the heat
sink 26, since one power module 25 is mounted on only one side of
the base surface 27 of the heat sink 26, the step of fixing the
power modules 25 to the heat sink 26 is more simple than the step
of placing the power modules 25 on both sides of the base surface
27.
In FIG. 6, the tins 32 of the heat sinks 26 combined in the heat
sink assembly 37 are divided in the shaft direction, and the areas
of the fins 32 are configured to be almost the same. This allows
the cooling capability of the heat sink 26 placed on the one side
to conform to that on the other side. It should be appreciated that
when there is a difference in the cooling capability between the
heat sinks 26 in mounting the rotary electric machine 1 on an
engine the division position may be changed to eliminate the
difference.
Furthermore, although the fins 32 are L-shaped in the shaft
direction in FIG. 6, if the fins 32 are rectangular, the fins 32
can be divided at the center, in which both the heat sinks 26 can
be the same and then the cost can be reduced.
FIG. 7 is a side view of the heat sink assembly 37 showing another
example of the shape of the fin 32 of the heat sink assembly 37 of
the third embodiment of the invention. In the heat sink assembly 37
in FIG. 7, the fins 32 of the heat sink 26 are divided into left
and right, side, then the divided fins 32 are combined into the
heat sink assembly 37. In this configuration, the two heat sinks 26
are cooled in the same way from the upstream to the downstream of
cooling air flow, so the two heat sinks 26 can be cooled
uniformly.
Specifically, the heat sink assembly 37 is divided into: a portion
as shown in FIG. 7(b) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31 and a fin 32
are provided; and a portion as shown in FIG. 7(c) in which one
power module 25 is mounted on a base surface 27 of one heat sink 26
and then a case 31 and a fin 32 are provided, and then these
portions are integrated into the heat sink assembly 37 as shown in
FIG. 7(a).
According to the third embodiment, the power module 25 including a
switching device for energizing armature current is fixed to the
base surface 27 of the heat sink 26, then the base surfaces 27 of
the heat sinks 26 are stacked with the power modules 25 aligned
with each other and fixed into the heat sink assembly 37, and then
a plurality of the heat sink assemblies 37 are mounted on the
rotary electric machine 1, which can provide an effect similar to
that of the above-described first embodiment. Furthermore, the
power module 25 is fixed to one side of the base surface 27 of the
heat sink 26, which can facilitate the fabrication to reduce the
manufacturing cost.
Furthermore, similarly to the above-described first embodiment, the
third embodiment is configured so that the fin 32 of the heat sink
26 protrudes in the radial direction, which allows reservation of a
larger area for the fin 32 of the heat sink 26. Furthermore, since
the rear-side fan 9 of the rotor 7 takes in air from the rotation
shaft direction and discharges air toward the periphery, the fin 32
is protruded toward the inner radius, which causes cooling air flow
to efficiently flow along the fin, resulting in enhancement of the
cooling capability of the rotary electric machine.
Fourth Embodiment
A fourth embodiment of the invention is described with reference to
FIGS. 8 to 10. Through the drawings, the same or corresponding
members or portions are denoted by the same numerals. FIG. 8 is an
axial cross-sectional view showing a heat sink assembly in a rotary
electric machine in accordance with the fourth embodiment of the
invention. FIG. 9 is an axial cross-sectional view showing the heat
sink assembly in the rotary electric machine in accordance with the
fourth embodiment of the invention. FIG. 10 is an axial
cross-sectional view showing the heat sink assembly in the rotary
electric machine in accordance with the fourth embodiment of the
invention.
Similarly to the above-described third embodiment, a heat sink
assembly 38 of the fourth embodiment is configured by mounting a
power module 25 on a base surface 27 of a heat sink 26, then
joining and fixing to each other the base surfaces 27 of the two
heat sinks 26 on which the power modules 25 are not mounted. A fin
36 protruding from the base surface 27 of the heat sink 26 is
configured to protrude in the circumferential direction of the
rotary electric machine 1.
The heat sink assembly 38 shown in FIG. 8 is configured in shape
such that the fin 36 of the heat sink 26 is divided at almost the
middle of the length in the shaft direction and the divided
portions are combined. Accordingly, the same heat sink 26 can be
used irrespective of position in the shaft direction when combined,
which can reduce the cost. When there is a difference in the
cooling capability of the heat sink 26 depending on the position in
the shaft direction, the division position can be changed so that
the cooling capability will be uniform.
Specifically, the heat sink assembly 38 is divided into: a portion
as shown in FIG. 8(b) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31, a
protection cover 34 and the fin 36 are provided; and a portion as
shown in FIG. 8(c) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31, a
protection cover 34 and the fin 36 are provided, and then these
portions are integrated into the heat sink assembly 38 as shown in
FIG. 8(a).
FIG. 9 is a side view of the heat sink assembly 38 showing another
example of the shape of the fin 36 of the heat sink assembly 38 of
the fourth embodiment of the invention. As shown in FIG. 9, when
the two heat sinks 26 are combined, the fins of the heat sinks 26
are arranged in a staggered configuration. In this configuration,
the two heat sinks 26 are cooled in the same way from the upstream
to the downstream of cooling air flow, so the two heat sinks 26 can
be cooled uniformly.
Specifically, the heat sink assembly 38 is divided into: a portion
as shown in FIG. 9(b) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31 and a fin 36
are provided; and a portion as shown in FIG. 9(c) in which one
power module 25 is mounted on a base surface 27 of one heat sink 26
and then a case 31 and a fin 36 are provided, and then these
portions are integrated into the heat sink assembly 37 as shown in
FIG. 9(a).
FIG. 10 is a cross-sectional view of the heat sink assembly 38
showing another example of the shape of the fin 36 of the heat sink
assembly 38 of the fourth embodiment of the invention. As shown in
FIG. 10, the fins 36 protruding in two circumferential directions
of the heat sink assembly 38 are configured such that one fin 36 of
one circumferential direction is configured on one heat sink 26,
then the combined heat sink assembly 38 configures the fins of two
directions. The fin 36 of the heat sink 26 for one direction can
enhance the manufacturability of the heat sink 26.
Specifically, the heat sink assembly 38 is divided into a portion
as shown in FIG. 10(b) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31, a
protection cover 34 and the fin 36 for one direction are provided;
and a portion as shown in FIG. 10(c) in which one power module 25
is mounted on a base surface 27 of one heat sink 26 and then a case
31, a protection cover 34 and the fin 36 for the other direction
are provided, and then these portions are integrated into the heat
sink assembly 38 as shown in FIG. 10(a).
Similarly to the above-described second embodiment, the fourth
embodiment is configured so that the fin 36 of the heat sink 26
protrudes in the circumferential direction, which allows
reservation of a larger area for the fin 36 of the heat sink 26.
Furthermore, since the rear fan 9 of the rotor 7 takes in air from
the rotation shaft direction and discharges air toward the
periphery, the fin 36 is protruded toward the inner radius, which
causes cooling air flow to efficiently flow along the fin,
resulting in enhancement of the cooling capability of the rotary
electric machine. Furthermore, similarly to the above-described
third embodiment, the fabrication can be facilitated to reduce the
manufacturing cost.
Fifth Embodiment
A fifth embodiment of the invention is described with reference to
FIG. 11 FIG. 11 is a cross-sectional view showing a heat sink
assembly in a rotary electric machine in accordance with the fifth
embodiment of the invention.
A power module 25 is fixed to a base surface 27 of a heat sink 26.
A case 31, into which a wiring to the power module 25 and the like
are inserted, is placed around the power module 25 on the base
surface 27. A terminal of the power module 25 is connected to the
case 31. Thus, a heat sink assembly 39 includes the heat sink 26,
the power module 25, the case 31, a fin 32 and a protection cover
34. Note that in the fifth embodiment, the fin 32 provided on the
heat sink 26 protrudes inwardly in the radial direction.
Furthermore, a signal member 40 for communicating signal of the
power modules 25 and a control circuit 23 is placed between the
base surfaces 27 of the heat sinks 26.
Specifically, the heat sink assembly 39 is divided into: a portion
as shown in FIG. 11(b) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31, a
protection cover 34 and the fin 32 are provided; and a portion as
shown in FIG. 11(c) in which one power module 25 is mounted on a
base surface 27 of one heat sink 26 and then a case 31, a
protection cover 34 and the fin 32 are provided, and then with the
signal member 40 sandwiched between the base surfaces 27 of the
heat sinks 26 of the both portions these portions are integrated
into the heat sink assembly 39 as shown in FIG. 11(a).
Next, the signal member 40 for communicating signal of the power
modules 25 and the control circuit 23 is placed so as to be
sandwiched between the base surfaces 27 of the heat sink 26 of the
heat sink assembly 39 such that the signal member 40 is aligned
with the two power modules 25 in the radial direction, then this
combination is arranged in the circumferential direction.
According to the fifth embodiment, after the power module 25 is
mounted on the heat sink 26, when the two heat sinks 26 are joined
to each other such that the power modules 25 are aligned with each
other, the signal member 40 including a signal line for controlling
the power modules 25 is placed between the base surfaces 27 of the
heat sinks 26, which allows the signal line to be protected.
Furthermore, the mountability on the rotary electric machine 1 can
be enhanced.
The heat sink assembly 39 configured as described above is mounted
on a housing of the rotary electric machine 1. In addition to the
heat sink assembly 39, a field circuit module 24 or the control
circuit 23 may be fixed to the heat sink 26.
Furthermore, a member including a ground wiring for connecting to
the power modules 25 and the like may be configured in a rear-side
housing 3, and a member including an output wiring may be
configured in the rear-side end face of the rotary electric machine
1 or a cover 29.
A power assembly configured as described above can be manufactured
and tested in a separate process, then a plurality of completed
power assemblies are mounted on a rotary electric machine at one
time, which facilitates the fabrication.
Note that the embodiments of the invention may be freely combined
or appropriately modified or omitted within the scope of the
invention.
INDUSTRIAL APPLICABILITY
The invention is suitable for providing a rotary electric machine
that can have sufficient cooling capability.
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